One thing about the 2010: When the car warms up, the muffler lowers. There is a bracket on the right of the muffler that ends up resting on the towbar, causing a terrible "grinding" sound when accelerating. Bending the bracket slightly away from the towbar solved this.

I would bet this is the same thing happening with my '09 128. I mounted the hitch last week and I've been getting an occasional rattle from the exhaust touch the hitch assembly. But I haven't really looked at it yet.